<%@ page language="java" pageEncoding="UTF-8"%>
<%
	response.setHeader("Pragma", "no-cache");           //HTTP   1.0 
	response.setHeader("Cache-Control", "no-store");    //HTTP   1.1 
	response.setHeader("Cache-Control", "no-cache");
	response.setHeader("Cache-Control", "must-revalidate");
	response.setDateHeader("Expires", 0);
	out.print("ok");
%>